Selector for electric connecting systems



Nov. 1, 1938. M. B. RICHTER 2,135,015

SELECTOR FOR ELECTRIC CONNECTING SYSTEMS Filed Aug. 4, 1936 LLNA) W I L LLJ V I FNVENTOR/ Mom; BHLTHHZAR, IBIcHTER/ v M M ATTMNEY Patented Nov. 1, 1938 UNITED STATES PATENT OFFICE Morten Balthazar Richter, Copenhagen, Denmark Application August 4, 1936, Serial No. 94,258 In Denmark August 16, 1935 Claims.

For electric connection systems, for instance automatic and semi-automatic telephone plants, it is common to use selectors with one or more rows of stationary contacts arranged along cir- -5 cular arcs and with one or more movable contacts adapted to move in circles each along one of these rows of contacts, all for the purpose of establishing a desired circuit connection across a contact in each of the said rows.

Selectors of this kind have to fill the requirement that the resistance to the adjusting motion of the selector must be very small, and that this motion should stop practically instantaneously when the selector, during its rotary motion, has found a desired circuit connection. Further, the contacts of the selector, even after a long use, must not be exposed to any Wear giving rise to vibrations and poor contact connection.

The selectors known heretofore do not fill these requirementsvto a sufficient extent, for instance because not only the movable contacts-the selecting contacts-which serve to find the circuit connection corresponding to a desired adjustment of the selector, but also the movable contactsthe so-called line contactsserving to effect the subsequent establishment of the circuit connection during the rotary motion of the selector, will slide on stationary contacts in the selector. This is also the case in the selectors known heretofore in which the movable contacts can slide radially on their supporting member which is adapted to rotate relatively to the stationary rows of contacts and, during an adjusting motion preceding the rotary motion parallel to the axis of rotation and, consequently, at right angles to thesaid rows of contacts, are withdrawn from the latter, in such a manner that during the last mentioned motion they will be out of contact with the same.

40 The present invention relates to a selector with rotary adjusting motion by which the above mentioned requirements are filled. The movable line contacts adapted to effect a selected circuit connection are, like in the last mentioned known selectors, disposed in such a manner in their supporting member that they can be displaced radially on the same, within certain limits, and according to the invention they are kept out of contact with the stationary line contacts during the rotary motion. For this purpose, the movable line contacts according to the invention are connected mechanically to the coupling means controlled electromagnetically in known manner and serving to couple together the rotary part of the 55 selector and the driving mechanism of the same,

in such a manner that they will be withdrawn radially and automatically from the stationary rows of contacts, when the selector is coupled to its driving mechanism, and are returned automatically into contact with the stationary contacts, for instance by means of springs or by the said coupling means, when the latter release the connection between the selector and theidriving means of the same.

Hereby the advantage is attained that during the rotary motion of the selector there will be no frictional resistance between the above mentioned stationary and movable line contacts, and. that the mechanical wear on the latter will be extremely small, and that the shape, of the contact surfaces can be adjusted in such a manner that the same, when the movable line contacts are moved into contact with the stationary line contacts, will oiier such an eliective resistance against the continued motion of the selector that the latter will stop practically instantaneously.

This circumstance involves again the advantage that the width of the stationary line contacts in the direction of rotation can be made small, and in a selector of given dimensions there will therefore be space for a larger number of fixed line contacts in each contact row than heretofore, in such a manner that the selector, in order to search a given number of contacts, during the course of a given time, may move considerably more slowly than the selectors known heretofore. This is a favourable condition for the instantaneous stopping of the rotary motion of the selector at the closure of contact between the movable and the stationary line contacts, and this instantaneous stopping may further be favoured in that the movable part of the selector is constructed with as small a mass as possible. In View hereof, the most preferable construction of the selector according to the invention is distinguished in that the electrcmagnet serving to control the coupling connection between the selector and the driving mechanism of the same is centrally disposed relatively to the selector, in such a manner that the iron core and the coil of the said electromagnet do not partake in the rotary motion. The iron core is used as a stationary pivot pin for the movable part of the selector, and the electromagnet coil encircling the iron core is supported by the iron core or the stationary part or base of the selector. On the other hand, the armature of the electromagnet is journalled about the rotary part of the selector in close connection with the said iron core, and is connected mechanically to the movable line contacts provided on the same part ofthe selector as well as to the coupling means supported by the same selector part and serving to couple the latter to a rotary driving disc.

In most of the said selectors, the desired circuit connections are effected each merely across one single stationary contact, and on the movable part of the selector there must consequently be provided a connection common to all the circuits. In consequence hereof, the said selectors cannot be used for selection between several mutually independent circuits, and their field of usefulness is therefore rather limited.

Selectors of the present nature may be rendered more universally useful by providing according to the invention, in the selector, besides the above mentioned line contacts-not like in the selectors known heretofore merely one-but, on the contrary, two separate sets of searching contacts consisting each of a contactthe movable searching contact-fixed on the movable se lector part, and of a row of stationary contacts arranged along a circular are, along which stationary contacts the movable searching contact can slide during the rotary motion of the selector. Hereby the advantage is attained that the various circuits, out of which the searching contacts will select the one that corresponds to a desired adjustment of the selector, and closes this circuit, in order thereby to cause the selector motion to stop, can be directed across tne selector independently of one another.

The further details of the invention appear from the following descri tion of the constructions of a selector shown on the drawing.

Fig. 1 shows a selector, in top view,

Fig. 2 the same in side elevation, partly in section,

Fig. 3 in perspective view, a portion of the selector shown in Figs. 1 and 2,

Fig. l a longitudinal section of a coupling member, and

Fig. 5 a bottom view of the same.

0, Figs. 1 and 2, is a support, shaped as a part of a cylinder, for the stationary line contacts i and 2 in a selector, the movable line contacts 3 of which are slideably supported on plates 34 of electric insulating material. In the manner further mentioned below, the said plates are slideably mounted on a supporting member 4 pivoted about a vertical axis A.

The supporting member 4 is attached to the bottom part of a mainly box-shaped casing 25 containing a not shown electromagnet-coil which encircles a vertical iron core 5. The casing 25 is pivotally mounted on this core in such a manner that the casing 25 and the supporting member 4 can be rotated about the axis of the iron core 5. The iron core 5 is stationary.

The electromagnet coil which is disposed in the casing 25, and in which the pin 25 forms the iron core, is inserted in a not shown control circuit which, by being closed, couples the movable part of the selector to a continuously rotating driving pulley [5.

The supporting member 4 for the movable contacts supports two plate pieces 9 standing edgewise and being made of iron or some other magnetic material. These plates rest with their bottom edges on the top side of the supporting memher 4 and extend each with a tongue 30 down through an incision in the supporting member. These two pieces of plate form the movable armature of the electromagnet consisting of the iron core 5 and the casing 25 and the electromagnet coil contained in the latter, the said armature being consequently divided in two. The upper end bottom of the casing 25 forms a pole shoe for the iron core 5. Two opposite edges 28 on the end bottom 2? face each one of the two armature parts 8, and attract the latter when current is supplied to the electromagnet.

The plates 34 carrying the movable contacts 3 are made from electrically insulating material, and are radially disposed relatively to the axis of rotation A, and they rest each partly on a part i bent upward from the supporting memher 4, and partly in slots 33, Fig. 3, in each of the armature parts 9, and the plates 34 are fixed in the said slots by means of pins 35, Fig. 2. On the bottom side of the supporting member 4, and on two diametrically opposite sides of the axis A, Figs. 2, 4 and 5, there are provided radially slideably coupling members 32, which are fixed to the supporting member 4 by means of screws 52 passing through oblong holes 55, Figs. 4 and 5, with incision 55 for the screw heads in the coupling members 32. The downward facing tongues 39 on the armature parts 9 extend down into a hole 3| in each of the coupling parts 32.

When the armature parts 9 are attracted by the edges 28 on the casing 25, the armature parts Will rotate about their bottom edges resting on the supporting member 4, and thereby the tongues 30 will push the coupling members 32 radially outward so as to rest on axial surface E4 of the continuously rotating driving pulley I5. The supporting member 4 and the parts attached thereto, i. e. the casing 25 on the electromagnet described above, the armature parts 9 and the plates 34 with the movable contacts are then set into rotation about the axis A.

At the same time as the armature parts 9 moved the coupling members 32 into contact with the driving pulley i by moving them radially outward, they pulled the plates 34 for the movable contacts radially inward, and thereby the free ends of the movable contacts 3 facing the stationary contacts were moved away from the said stationary contacts I and 2, cf. the positions 3 shown by dotted lines in Fig. 2.

In the construction shown, three movable contacts situated axially above one another are provided on each of the plates 34. The said movable contacts consist each of a thin metal lamina fitted with two slots 36 and 31, by means of which the metal lamina engages pins 38 and 39, respectively, on the plates 34, in such a manner that each of the contacts 3 can be displaced radially, but not axially, on the plates 34.

Between bent flaps 40 on each of the contacts 3 and the pins on the plates 34 that engage the slots 31, helical springs 4| are inserted which tend to press the line contacts 3 radially outward against the stationary line contacts I and 2, but when the armature parts 9 are attracted, are prevented from doing this, owing to one of the pins 33 and 39 resting then against the end of the slot 36 and 3'! concerned in the contacts 3 that faces the axis A. As appearing from the above description, the line contacts 3 will not rest against the stationary contacts I and 2 during the rotary motion of the selector.

The two armature parts 9 are coupled together by being each fitted with two flaps 24 bent at right angles cf. Figs. 2 and 3, and extending along each side of the casing 25. The two flaps 24 of the armature parts, on the same side of the casing, engage one another, a projection 49 on one of the said flaps engaging an incision in the other flap. The said flaps form thus a linked connection between the two armature parts 9.

As appearing from Fig. 1, the selector supports, on diametrically opposite sides of the supporting member 4, two sets of movable line contacts 3, one of which sets moves out of the range of the stationary line contacts I and 2, when the other set enters in front of the same during the rotation of the selector in the direction shown by the arrow in Fig. 1.

In consequence of the linked connection between the armature parts 9 formed by the flaps 24, the said armature parts will co-operate so as to effect a radial displacement of the set of movable line contacts 3 that at any time is standing opposite the stationary line contacts.

The stationary line contacts I and 2 are insulated mutually and from the supporting member 0, and are constructed as contact springs. The individual contact sets comprise each the number of stationary line contacts I and 2 that are selected simultaneously by the movable line contacts 3 placed above one another, i. e. in general all the contacts I and 2 situated in one and the same section through the axis of rotation A of the selector, and in the individual contact sets the said contacts are disposed in such a manner that they are short-circuited in pairs by the movable line contacts 3, when the latter are adjusted to the set of contacts concerned.

The circuits that have to be connected by means of the selector are connected each to the corresponding separate pair of stationary line contacts I and 2, in such a manner that the said circuits are closed, when the line contacts concerned are short-circuited by a contact 3.

Besides the line contacts I and 2, each set of stationary contacts contains two searching contacts ll. The latter are connected to the circuit that by being connected across these contacts and the movable searching contacts I6 sliding thereon have to cause the adjusting motion of the selector to stop.

There being provided, for each short-circuiting in the selector, two stationary line contacts across which the desired connection is established, Viz. by a single short-circuiting of these contacts, all the circuits, if desired, may be maintained entirely separated, and thereby the field of usefulness of the selector becomes wider than for the selectors known heretofore, and the stationary sets of contacts may for instance be connected group-wise or single each to one of several dilferent outer systems that are desired to be served by one and the same selector, and for instance one single selector of the above described kind may control line searches as well as group selectors and line selectors or other similar systems by dividing that stationarycontacts of the selector into groups connected separately to one or the other of the said systems.

The stationary rows of contacts I and 2 cover an arc of 180. During the course of each full revolution of the supporting member 4, all of the stationary contacts I and 2 will therefore be searched twice, there being provided two sets of movable contacts 3, as mentioned above.

When the above mentioned control circuit, by means of which the electromagnet serving to adjust the armature parts '3 is rendered operative, is broken owing to the contacts I6 reaching forward to the contacts I! in an idle set of contacts during the adjusting motion of the selector, the armature parts will be swung away from the casing 25 by the action of the spring I2, and

thereby the coupling members 32 will be pressed back from the face I4 on the driving pulley I5, at the same time as the ends of the movable contacts 3 that face the contacts I and 2 are moved radially outward so as to rest against the contacts I and 2 that at the given moment stand opposite the movable contacts. The armature 4 and consequently all the parts carried by the same will thereby stop their motion.

' The free ends of the movable line contacts 3 are wedge-shaped, and at the short-circuiting they will enter between the contacts I and 2, and will short-circuit the same.

The movable searching contacts I6 are each divided into two, in such a manner that they will encircle the stationary searching contacts I! and rest against both sides of the same. The movable searching contacts I6 are attached to an insulated supporting member 50 on the supporting member 4, the attachment of the former to the latter being effected by means of bolts 5|. These bolts pass through slots 52 in the supporting members 55, and thereby it becomes possible to adjust the latter and, thereby, the contacts Iii in planes perpendicular to the axis of rotation A. The outer ends 53 of the contacts I6 are bent, as appearing from Fig. 1, and the two superimposed parts of each of the contacts I6 are in contact along the edges of the bent parts pointing rearward in the direction of motion, but are separated slightly from one another at the edges pointing forward in the direction of the, motion, also when the edges l6 are not touching the contacts I'I. Hereby it will be certain that the two parts of a contact I6 will always move inward about a stationary contact I], and will always rest against both sides of the latter with a resilient pressure during the motion of the selector.

It should be noted that the coupling members 32 which act by friction against the face I4 on the driving pulley I5 may be replaced by pawls co-operating with a circular row of teeth or with axial grooves or cams on the inner face, and that the number of line contacts and searching contacts in a set of contacts is arbitrary.

As mentioned above, the rotary motion of the supporting member 4 and the parts attached thereto will stop when the electromagnet disposed in the casing 25 is rendered current-less. When this is the case, the motion of the selector should stop momentaneously, and therefore the vis viva of the moving part should be as small as possible. This is attained by the process de scribed above, in that the electromagnet is placed centrally relatively to the selector, in such a manner that the coil and iron core of the electromagnet do not partake in the rotary motion, and that the other movable parts of the selector are constructed with only a small mass, and that the armatures of the electromagnet which partake in the rotary motion are placed as near as possible to the axis A. In order further to ensure that the motion of the selector should stop practically instantaneously when the magnet in the casing 25 becomes currentless, there may be provided, in connection with the said casing, a pawl mechanism which after the armature parts have been released by the electromagnet will instantaneously stop any further motion of the selector. For this purpose, the upper end of the iron core 5 projecting through the casing 25 is fitted with a stationary ratchet wheel 42 engaged by four pawls 45, cf. Fig. 1. Each of the said pawls is pivoted to the top side of the casing 25, in such a manner that they can swing about pins 8, and are maintained in engagement with the ratchet wheel 42 by means of springs 46, which are inserted each between two pawls disposed on the same side of the casing 25.

When the armature parts 9 are attracted, pins or projections 48 on the same will strike the free ends ll of the pawls, and will thereby disengage the latter from the ratchet wheel 42, in such a manner that the casing 25 and the supporting member 4 can be rotated. The ratchet wheel does not partake in this rotary motion. When the electromagnet becomes current-less, and the armature parts 9 consequently move away from the edges 28 of the casing 25, the springs 26 will at once cause the pawls to engage the ratchet wheel 42.

The four pawls 45 are adjusted in such a manner that for an angular motion corresponding to one quarter of the pitch of the ratchet wheel 42, one of the pawls will always slide into engagement with a tooth on the ratchet wheel, in such a manner that the lost motion of the latter and, consequently, or" the rotary part of the selector can never exceed one quarter of the pitch of the ratchet wheel. Hereby a practically momentaneous stop of the selector will be attained.

Having now particularly described and ascertained the nature of my invention and in what manner the same is to be performed I declare that What I claim is:-

1. A selecting switch of the power driven type for electric connecting systems, comprising a plurality of stationary terminals arranged in a number of circular arcs, a rotatable member centrally disposed relatively to said arcs, a driving member, adjustable means to couple said rotatable member to said driving member, two sets of movable contacts adjustably mounted on said rotatable member on opposite sides of the central portion of same so as to be shifted radially on same to engage by turns the stationary terminals, two upright disposed levers supported at their lower ends upon the rotatable member on either side of the axis of revolution of same, an electromagnet engaging said levers to swing them when the electromagnet is energized, means to connect each of said sets of movable contacts to one of said levers, and means connecting the levers to the means for coupling the rotatable member to the driving member, in order that the two levers, when swung by the action of the electromagnet, are caused to shift said sets of movable contacts radially away from the arc of stationary terminals and simultaneously to shift the means for coupling the rotatable member and the driving member so as to intercouple said two members.

2. A selecting switch of the power driven type for electric connecting systems, comprising a plurality of stationary terminals arranged in a number of circular arcs, a rotatable member centrally disposed relatively to said arcs, a driving member, adjustable means to couple said rotatable member to said driving member, two sets of movable contacts adjustably mounted on said rotatable member on opposite sides of the central portion of same so as to be shifted radially on same to engage by turns the stationary terminal, two upright disposed interlinked levers freely supported at their lower ends upon the rotatable member on either side of the axis of revolution of same, an electromagnet engaging said levers to swing them when the electromagnet is energized, means to connect each of said sets of movable contacts to one of said levers, and

means connecting the levers to the means for coupling the rotatable member to the driving member, in order that the two levers, when swung by the action of the electromagnet, are caused to shift said sets of movable contacts radially away from the arc of stationary terminals and simultaneously to shift the means for coupling the rotatable member and the driving member so as to intercouple said two members.

3. A selecting switch of the power driven type for electric connecting systems, comprising a plurality of stationary terminals arranged in a number of circular arcs, a rotatable member centraliy disposed relatively to said arcs, a driving member, adjustable means to couple said rotatable member to said driving member, two edgewise disposed plates of electric insulating material adjustably mounted on the rotatable member so as to extend radially at opposite directions relatively to the axis of revolution of the rotatable member, two upright disposed interlinked levers freely supported at their lower ends upon the rotatable member on either side of the axis of revolution of same, an electromagnet engaging said levers to swing them when the electromagnet is energized, a number of radially disposed resiliently mounted movable contacts on each of said edgewise disposed plates of electric insulating material, means to connect each of said plates to one of said levers, and means connecting the levers to the means for coupling the rotatable member to the driving member, in order that the two levers, when swung by the action of the electromagnet, are caused to shift said sets of movable contacts radially away from the arcs of stationary terminals and simultaneously to shift the means for coupling the rotatable member and the driving member so as to intercouple said two members.

4. A selecting switch of the power driven type for electric connecting systems, comprising a plurality of stationary terminals arranged in a number of circular arcs, a rotatable member centrally disposed relatively to said arcs, a driving member, adjustable means to couple said rotatable member to said driving member, two edgewise disposed plates of electric insulating material adjustably mounted on the rotatable member so as to extend radially at opposite directions relatively to the axis of revolution of the rotatable member, two upright disposed interlinked levers freely supported at their lower ends upon the rotatable member on either side of the axis of revolution of same, an electromagnet engaging said levers to swing them when the electromagnet is energized, a number of radially disposed and resiliently and adjustably mounted contacts on each of said edgewise disposed plates of electric insulating material, springs connecting each of said contacts separately to the plate, separate means to support each of said contacts upon said plate so as to allow each contact when engaging the terminals by the action of said spring to adjust itself radially as well as axially to properly interconnect two of the stationary terminals, means to connect each of said plates to one of said levers, and means connecting the levers to the means for coupling the rotatable member to the driving member in order that the two levers, when swung by the action of the electromagnet, are caused to shift said sets or movable contacts radially away from the arc of stationary terminals and simultaneously to shift the means for coupling the rotatable member and the driving member so as to intercouple said two members.

5. A selecting switch of the power driven type for electric connecting systems, comprising a plurality of stationary terminals arranged in a number of circular arcs, a rotatable member central- 1y disposed relatively to said arcs, a driving member, adjustable means to couple said rotatable member to said driving member, two edgewise disposed plates of electric insulating material adjustably mounted on the rotatable member so as to extend radially at opposite directions relatively to the axis of revolution of the rotatable member, two upright disposed interlinked levers freely supported at their lower ends upon the rotatable member on either side of the axis of revolution of same, an electromagnet engaging said levers to swing them when the electromagnet is energized, a number of radially disposed and resiliently and adjustably mounted contacts on each of said edgewise disposed plates of electric insulating material, springs connecting each of said contacts separately to the plate,

separate means to support each of said contacts upon said plate so as to allow each contact when engaging the terminals by the action of said spring to adjust itself radially as Well as axially to properly interconnect two of the stationary terminals, means to connect each of said plates to one of said levers, and means connecting the levers to the means for coupling the rotatable member to the driving member in order that the two levers, when swung by the action of the electromagnet, are caused to shift said sets of movable contacts radially away from the arc of sta tionary terminals and simultaneously to shift the means for coupling the rotatable member and the driving member so as to intercouple said two members, and springs interconnecting the lower portions of the two levers so as to swing them to pull said coupling means out of engagement with the driving member and to bring one set of movable contacts into engagement with stationary terminals when the electromagnet is deenergized.

MORTEN BALTHAZAR RICHTER. 

